in the extraction process of some secondary metabolites from bacteria, we are sometimes using an organic solvent such as, ethyl acetate or resins such as XAD. why?
Your question is not clear. Ethyl acetate is organic solvent (liquid) to extract organic compound from the sample. XAD is solid polymer (not liquid), so you are comparing two different things. Need to see the detail of protocol before I can answer this question. Since it is your protocol (in your lab), you should ask the author of that protocol.
Dear Sir. Concerning your issue about the extraction process of some secondary metabolites from bacteria.The extraction is done by ethyl acetate and then the crude extract was run in the column chromatography. For more detail, I think the following below links may help you in your analysis: